package edu.kit.csl.pisa.training.eva2;

/*
This file is part of the PISA Alignment Tool.

Copyright (C) 2013
Karlsruhe Institute of Technology
Cognitive Systems Lab (CSL)
Felix Stahlberg

PISA is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

PISA is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with PISA. If not, see <http://www.gnu.org/licenses/>.
*/

import edu.kit.csl.pisa.datatypes.Alignment;
import eva2.tools.math.RNG;

/**
 * This mutator moves a word boundary at random position by one phoneme to the
 * left or right.
 * 
 * @see edu.kit.csl.pisa.datatypes.Alignment#realign(int, int)
 */
public class MutateRealign extends MutateAlignment {

	private static final long serialVersionUID = -7874435893545343064L;

	/**
	 * {@inheritDoc}
	 * @see edu.kit.csl.pisa.datatypes.Alignment#realign(int, int)
	 */
	@Override
	protected void mutate(Alignment alignment) {
		int trgtWordIdx = alignment.getRandomFreeTargetWordIndex();
		if (trgtWordIdx >= 0 &&
				alignment.countSourceWords() > 1) {
			alignment.realign(trgtWordIdx,
					RNG.randomInt(0, alignment.countSourceWords() - 1));
		}
	}
}
